“Contested primaries are so good for America’s political process! Competition makes everyone work harder, be more efficient, debate clearer and produce more," the 2008 GOP vice presidential nominee wrote on her Facebook page. "So, Alaskans should be thrilled that Joe Miller jumped in the GOP race and is ready, willing and able to serve us as our next United States senator.”

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“I’m proud to join so many other long-time Alaskans in supporting Joe Miller in the upcoming Alaska Republican primary,” Palin added. “Joe is a true commonsense constitutional conservative, and we’re thankful he and his family are willing to offer us a choice in Alaskan leadership.”

Responding to Palin's endorsement of Miller, Murkowski communications director Steve Wackowski said: “Lisa fights every day for Alaska and has a proven track record and commitment to serving our state, and she fully plans to campaign for the privilege to continue to serve the best interests of Alaska.”

Palin has a long history of battling with the Murkowskis, beginning in 2006 when Palin unseated the senator’s father, Frank, in the Republican gubernatorial primary.

The former governor has long associated the rival family with the “machine” politics she says ran the state before she came on the scene. Also, when Palin resigned as governor, Murkowski said Palin had chosen to “abandon” the state, contributing to rumors of bad blood between the two camps.

At one time, Palin was believed to have wanted to run for Murkowski’s seat, but the former governor deflated the rumors when she contributed to the senator’s campaign.

In her Facebook post, she explained herself.

“Over a year ago, upon kicking off our political action committee to assist candidates and promote competition in the nation’s electoral system, with no one willing to challenge the political machine at the time, and amid rumors that I would challenge Lisa Murkowski for the U.S. Senate, SarahPAC contributed to Lisa’s campaign,” Palin wrote. “As she and I discussed, this was an attempt to reassure the senator that I, as Alaska’s governor, had no intention of jumping into the race.”

“Though the media has tried to portray some sort of feud or bad blood between Lisa and myself, such is not the case,” Palin wrote. “I’ve always wished her well, but it is my firm belief that we need a bold reformer who is not afraid to stand up to special interests and take on the tough challenges of our time. Joe Miller has stepped forward. I am thankful for his willingness to serve," Palin wrote.

"He has fought alongside me and others to help clean up the Republican Party here in Alaska by bringing in new leadership, new ideas, and commitment to putting government back on the side of the people, not any political machine.”